1. Field of the Invention
The present invention relates to a universal control scheme associated primarily with the hydraulic system for construction or demolition equipment, wherein the equipment is intended for use with hydraulic attachments such as a bucket, a cutting shear, a grapple, a hammer, a magnet or the like.
2. Description of Related Art
Throughout the application, reference will be made to construction equipment. However, the equipment is also referred to as demolition equipment, scrap handling equipment and the like. The description of construction equipment is not intended to be restrictive of the equipment being referenced. Construction equipment such as heavy-duty metal cutting shears, grapples, and concrete crushers, have been mounted on backhoes powered by hydraulic cylinders for a variety of jobs in the demolition field. This equipment provides for the efficient cutting and handling of scrap. For example, in the dismantling of an industrial building, metal scrap in the form of various diameter pipes, structural I-beams, channels, angles, sheet metal plates and the like must be efficiently severed and handled by heavy-duty metal shears.
However, typically such shears are detachably connected to the hydraulic cylinder such that, if the hydraulic cylinder is intended to be used for a different application, such as digging with a bucket, then the shears may be removed and the bucket may be attached to the hydraulic cylinder for the desired application.
FIG. 1 illustrates the hydraulics associated with a construction machine 10, such as a backhoe. In particular, the many functions of the backhoe are powered by hydraulic fluid, whereby an engine 12 operates hydraulic pumps 14 which take hydraulic fluid from a hydraulic tank 16 and provide it to a plurality of control valves 18. A plurality of hydraulic lines extend from the control valves 18 to different accessories and tools on the backhoe 10. In particular, a boom 20 pivotally attached to the base platform is operated by a boom hydraulic cylinder 24 powered by fluid from the control valves 18. In a similar fashion, a stick 26 and a bucket 28 are pivotally manipulated by associated hydraulic cylinders powered with fluid provided from one of the control valves 18. The platform 22 may be pivoted about the base 30 utilizing a hydraulic swing motor 32, again powered by hydraulic fluid supplied through one of the control valves 18. In general, the control valves 18 are operated within the backhoe cabin (not shown) by the use of two separate joysticks that may be pivoted in different directions and with buttons that may be associated with each of these joysticks.
Oftentimes, hydraulic equipment such as the backhoe illustrated in FIG. 1, may be reconfigured to perform different functions by substituting different parts of the backhoe.
In particular, FIG. 2 illustrates a construction machine 10 which has attached to the stick 26, a shear 35 for which the jaws 36, 38 open and close but, for which also the body 40 rotates about the shear axis 41. It should be appreciated that there is at least one additional function for the construction machine 10 illustrated in FIG. 2 beyond that shown for the construction machine illustrated in FIG. 1. In particular, the shear jaws 36, 38 are capable of opening and closing. Additionally, the body 40 is capable of rotating about its axis 41. Therefore, in order to configure the construction machine 10 illustrated in FIG. 1, it would be necessary to add an entire hydraulic circuit to control the hydraulic motor which would rotate the shear about its axis 41 or, which would open and close the jaws 36, 38, or both.
FIG. 3 illustrates a construction machine 10 which utilizes a grapple 44 attached to the stick 26 whereby, once again, the grapple 44 is capable of rotating about an axis 45 extending therethrough and, once again, a new hydraulic circuit would be required to power the hydraulic motor to rotate the grapple 44 about its axis 45 and/or to open and close the jaws of the grapple 44. The construction machine 10, as illustrated in FIGS. 1-3, utilizes a hydraulic motor to rotate the attachments about their axes. It should be appreciated that the control valve associated with this function is capable of reversing flow through the hydraulic motor so that the rotation of the tool may occur in either direction. Under these circumstances, the circuit that provides this function must include a control valve capable of reversing flow.
FIG. 4 illustrates a construction machine 10 having a hammer 47 attached to the stick 26. Once again, a separate hydraulic function is required to operate the hammer 47. However, unlike the previous configurations, the hammer 47 does not utilize a hydraulic motor capable of reversing, but only utilizes hydraulic fluid under pressure in a single direction to reciprocate the tip of the hammer. This requires the addition of yet another hydraulic line pair having associated therewith a hydraulic valve which does not reverse the flow because, under such circumstances, reversal is not needed.
FIG. 5 illustrates a construction machine 10 having an electric magnet 50 attached to the stick 26.
As can be appreciated, the reconfiguration of a single construction machine may be very involved and hydraulic line pairs used to operate accessories and equipment must be found at different locations on the construction machine 10.
FIG. 6 illustrates a schematic of a simple hydraulic system similar to that which may be associated with the construction machine 10 shown in FIG. 1.
To the extent that the construction machine 10 illustrated in FIG. 1 is designed for the sole purpose of manipulating a bucket 28, then the control valves 18 may be dedicated to particular hydraulic fluid lines, which themselves are dedicated to a particular function on the construction machine 10. In FIG. 6, the hydraulic tank 16 provides fluid to the pump 14 which supplies hydraulic lines 52, 54, 56 connected to associated control valves 58, 60, 62 to control the flow of hydraulic fluid to achieve different functions, for example, functions F1, F2, F3. Directing attention to FIG. 1, function F1 may be manipulating the hydraulic cylinder associated with the boom 20, function F2 may be controlling fluid to the hydraulic cylinder associated with the stick 26, while function F3 may be associated with providing hydraulic fluid to the cylinder which curls and extends the bucket 28. Nevertheless, when the function of each control valve 58, 60, 62 and the associated accessories/tools are determined, design of the hydraulic system to perform this task is relatively straightforward and a controller capable of selectively opening and closing each of the control valves 58, 60, 62 is also relatively simple.
With the expense associated with a construction machine 10, construction machine owners desire to maximize the flexibility of the construction machine 10, not only to alleviate the need to purchase multiple construction machines, but furthermore, to permit the machine owner to purchase a set of complete tools and accessories that may be used on a single construction machine 10.
Additionally, in the past and at best, when different construction machines 10 performed different functions, depending upon the manufacturer of the construction machine and the design of the controller for the control valves, the motion of the joysticks for example, could be different from manufacturer to manufacturer. As a result, the machine operator would be required to learn the protocol of each controller associated with each manufacturer's construction machine prior to using that machine even though the final function between two machines would be identical. This not only provides a substantial learning curve for each different machine, but furthermore, introduces an element of risk when a machine operator changes between different construction machines. A construction machine is needed with the versatility to accept any number of different accessories and/or tools and, furthermore, to provide a central controller capable of controlling each of these functions in a relatively uniform and logical fashion. This would permit a machine operator to learn a protocol associated with each operation, wherein such a protocol will be the same between different machines utilizing the same design.